Lithium ion battery active substance diaphragm forming device

Abstract

The utility model belongs to the field of battery testing, and particularly relates to a lithium ion battery active material diaphragm forming device which comprises a sample accommodating part and a pressurizing part, the sample accommodating part comprises a base and a binding ring arranged in the base; and the pressurizing part comprises a pressing sheet arranged above the binding ring and a power part for applying pressure to the pressing sheet. The lithium ion battery active material diaphragm forming device is simple and convenient, active material powder cake pressing forming can be achieved manually, the structure of the powder forming device is simplified, and the device cost is reduced.

Description

Technical Field

[0001] The utility model belongs to the field of battery testing, and particularly relates to a forming device for a lithium-ion battery active material diaphragm. Background Art

[0002] Lithium-ion batteries have the advantages of high voltage, high energy density, long cycle life, low self-discharge, high safety, etc. At present, they have become the main driving power sources in application fields such as new energy electric vehicles, energy storage power stations, laptop computers, and smart phones.

[0003] Active material is an important component in the battery. Its compatibility with the binder affects the stability of the electrode, and further affects the comprehensive performance of the battery. Studying the compatibility between the active material and the binder is of great significance. Through the wettability test, the compatibility between the two can be quickly evaluated. The wettability test requires ensuring that the solid phase has a relatively flat interface. Pressing the active material powder into a cake to form a diaphragm can solve this technical problem.

[0004] In the existing powder forming technology, mainly the powder sample is placed into the mold. After assembly, the mold is pressurized by a mechanical lifting device to realize powder tablet forming. However, this device has a complex structure, and the tablet diameter is relatively small, usually less than 16 mm, which is not convenient for relevant tests. In addition, due to the weak intermolecular force of the active material, the powder is extremely easy to disperse during the demolding process. Summary of the Utility Model

[0005] The purpose of the utility model is to overcome the defects in the prior art and provide a forming device for a lithium-ion battery active material diaphragm.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A forming device for a lithium-ion battery active material diaphragm includes a sample accommodating component and a pressing component; the sample accommodating component includes a base and a binding ring arranged in the base; the pressing component includes a tablet arranged above the binding ring and a power component for pressing the tablet.

[0008] The power component includes a base screw cap and a pressing top cover connected to the base screw cap; a power output end passing through the pressing top cover is arranged on the pressing top cover; the power output end is in contact with the tablet.

[0009] The base is threadedly connected to the base screw cap.

[0010] The pressing top cover includes a cover body, an internal gear connected to the cover body by a bald head contact, and a power output end connected to the internal gear.

[0011] The power output end is a screw; an installation hole is provided on the base cover; the screw is in threaded connection with the installation hole.

[0012] A gasket is provided inside the base.

[0013] The inner diameter of the restraint ring is matched with the outer diameter of the pressing sheet.

[0014] Both the restraint ring and the pressing sheet are arranged between the base cover and the base.

[0015] The inner diameter of the restraint ring ≥ 40 mm; the height of the restraint ring ≥ 5 mm.

[0016] It further includes a test support sheet.

[0017] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0018] The lithium-ion battery active material film forming device of the present utility model is simple and convenient. The powder can be pressed into a cake to form a film by hand, which simplifies the structure of the powder forming device, reduces the device cost. By restricting the inner diameter of the restraint ring, the diameter of the pressed active material film can be made greater than 40 mm, which is convenient for the wettability test. Moreover, the pressed active material powder cake can be transferred, and the powder cake can maintain its original shape without scattering during the transfer process, realizing the rapid evaluation of the compatibility between the active material and the binder. Description of the Drawings

[0019] Figure 1 is an overall structural schematic diagram of the explosion state of the lithium-ion battery active material film forming device of the present utility model;

[0020] Figure 2 is a structural schematic diagram of the combination of the lithium-ion battery active material film forming device of the present utility model;

[0021] Figure 3 is a structural schematic diagram of the pressure top cover of the lithium-ion battery active material film forming device of the present utility model;

[0022] Figure 4 is a structural schematic diagram of the test support sheet of the lithium-ion battery active material film forming device of the present utility model. Detailed Embodiments

[0023] In order to enable those skilled in the art of the present technology to better understand the technical solutions of the present utility model, the present utility model will be further described in detail below with reference to the drawings and the best embodiments.

[0024] Figures 1-4Disclosed is a forming device for a lithium-ion battery active material diaphragm, comprising a sample accommodating component and a pressing component;

[0025] The sample accommodating component includes a base 3 and a restraint ring 4 arranged inside the base; the pressing component includes a pressing sheet 3 arranged above the restraint ring 4 and a power component for applying pressure to the pressing sheet.

[0026] The power component includes a base screw cap 2 and a pressing top cover 1 connected to the base screw cap; a power output end 11 passing through the pressing top cover is arranged on the pressing top cover; the power output end 11 is in contact with the pressing sheet 3.

[0027] The base 6 is threadedly connected to the base screw cap 2.

[0028] The pressing top cover 1 ( Figure 3 shown) includes a cover body 12, an internal gear 14 in contact connection with the cover body 12 through a bald head 13, and a power output end 11 connected to the internal gear 14.

[0029] The power output end 11 is a screw; an installation hole is arranged on the base screw cap; the screw is threadedly connected to the installation hole.

[0030] A gasket 5 is arranged inside the base.

[0031] The inner diameter of the restraint ring 4 is matched with the outer diameter of the pressing sheet 3.

[0032] Both the restraint ring 4 and the pressing sheet 3 are arranged between the base screw cap 2 and the base 5.

[0033] The inner diameter of the restraint ring ≥ 40 mm; the height of the restraint ring ≥ 5 mm.

[0034] It further includes a test support sheet 7.

[0035] The using method of the forming device for a lithium-ion battery active material diaphragm specifically includes the following steps:

[0036] First step, place a gasket 2 on the base 1, and then place the restraint ring 3 on the gasket 2; add the sample powder to be formed, and the powder sample can be graphite powder, or lithium iron phosphate powder, lithium cobalt oxide powder, conductive agent powder, etc. (graphite powder is taken as an example for illustration in this application). After spreading the powder flat, add the pressing sheet 3, gently press and ensure the flatness of the interface to complete the assembly of Group A components. Note that the added sample powder needs to be quantified.

[0037] Second step, screw the base screw cap 2 and the pressing top cover 1 together to complete the assembly of Group B components.

[0038] In the third step, twist Group A and Group B together, i.e., tightly screw the base cover 2 and the base 6, and then tightly screw the pressure top cover 1. After hearing three "click" sounds, the tightening action is completed, and the sample powder completes the action of forming a pressed cake.

[0039] In the fourth step, unscrew the pressure top cover 1 and the base cover 2 in sequence, invert the formed pressed cake on the test carrier 7, and then relevant tests can be carried out on the powder sample.

[0040] In a specific embodiment, the lithium-ion battery active material diaphragm forming device is cleaned and kept dry, and placed on the operating table.

[0041] In the first step, place the gasket 2 on the base 1, then place the restraint ring 3 (the inner diameter of the restraint ring 3 is 42 mm and the height is 10 mm) on the gasket 2, add 30 g of graphite powder sample with a spatula and spread it flat, add the component pressing sheet 4, and perform a slight press to complete the assembly of Group A components.

[0042] In the second step, screw the base cover 2 and the pressure top cover 1 together to complete the assembly of Group B components.

[0043] In the third step, twist Group A and Group B together, i.e., after tightly screwing the base 6 and the base cover 2, screw the pressure top cover 1. After hearing three "click" sounds, the tightening action is completed, and the graphite powder completes the action of forming a pressed cake. This is because as the tightening action occurs, the pressure between the screw at the bottom of the pressure top cover 1 and the pressing sheet 3 continuously increases. According to the friction formula f = u * N, the friction force f1 between the screw at the bottom of the pressure top cover 1 and the pressing sheet 3 gradually increases. The screw at the bottom of the pressure top cover is fixedly connected to the internal gear 14, and the friction force between the internal gear 14 of the pressure top cover 1 and the bald head 13 on the inner wall of the pressure top cover is f2. When f2 < f1, the "click" sound will be heard. At this time, the internal gear no longer rotates, that is, the tightening action no longer occurs, thereby ensuring that the force applied to the powder sample during tightening is constant.

[0044] In the fourth step, unscrew the pressure top cover 1 and the base cover 2 in sequence, invert the formed pressed cake on the test carrier 7, and then tests such as the wettability of graphite and the binder can be carried out. After measurement, the size of the graphite pressed cake is 42 mm in diameter and 7 mm in height. After calculation, the compaction density of the pressed cake is 3.16 mg / mm3.

[0045] In summary, it can be seen that the lithium-ion battery active material film forming device of the present utility model is simple and convenient. The powder can be pressed into a cake and then formed into a film manually, which simplifies the structure of the powder forming device and reduces the device cost. By restricting the inner diameter of the binding ring, the diameter of the pressed active material film can be made larger than 40 mm, which is convenient for the wettability test. Moreover, the pressed active material cake can be transferred, and the cake can maintain its original shape without scattering during the transfer process, realizing the rapid evaluation of the compatibility between the active material and the binder.

[0046] The above content is only the preferred embodiment of the present utility model. For those of ordinary skill in the art, according to the idea of the present utility model, there will be changes in the specific implementation manner and application scope. The content of this specification should not be construed as a limitation to the present utility model.

Claims

1. A lithium ion battery active material film forming device, characterized in that: It comprises a sample holding component and a pressurizing component; the sample holding component comprises a base and a restraining ring arranged in the base; the pressurizing component comprises a pressing sheet arranged above the restraining ring and a power component for applying pressure to the pressing sheet; The power component comprises a base rotary cover and a pressurized top cover connected to the base rotary cover; the pressurized top cover is provided with a power output end passing through the pressurized top cover; the power output end is provided in contact with the pressing sheet.

2. The lithium ion battery active material film forming device according to claim 1, characterized in that: The base is threadably connected to the base screw cover.

3. The lithium ion battery active material film forming device according to claim 1, characterized in that: The pressurized top cover comprises a cover body, a built-in gear connected to the cover body through a bald head, and a power output end connected to the built-in gear.

4. The lithium ion battery active material film forming device according to claim 3, characterized in that: The power output end is a screw rod; a mounting hole is arranged on the base rotary cover; and the screw rod is threadedly connected to the mounting hole.

5. The lithium ion battery active material film forming device according to claim 1, characterized in that: A gasket is arranged inside the base.

6. The lithium ion battery active material film forming device according to claim 1, characterized in that: The inner diameter of the restraining ring is matched with the outer diameter of the pressing sheet.

7. The lithium ion battery active material film forming device according to claim 6, characterized in that: The restraining ring and the pressing sheet are both arranged between the base rotating cover and the base.

8. The lithium ion battery active material film forming device according to claim 1, characterized in that: The inner diameter of the restraining ring is ≥40mm; the height of the restraining ring is ≥5mm.

9. The lithium ion battery active material film forming device according to claim 1, characterized in that: A test tray is also included.

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